Short answer: It is by design.
If one of Opera’s list providers has identified malware on a website, but other browsers have missed it, that is a good thing for Opera, not a bad thing. Other browsers have failed to detect it.
Opera does not provide its own malware blacklists. You can see which list provider has detected the malware by clicking the “Why was this page blocked?” link on the warning page in Opera.
You are seeing the “Fraud warning page” because the page you want to visit is listed as dangerous on some blacklists. Opera does not maintain its own phishing, fraud, or malware blacklist. The blacklists are provided by several partners, such as PhishTank and APWG for phishing and fraud, and Yandex for malware. If you think…
Opera does not maintain its own phishing, fraud, or malware blacklist. If you feel that our browser failed to recognize a fraudulent or malicious website, you can contact the following companies to have the URL added to their blacklists (after they have tested the sites). Opera will then use the updated blacklists as soon as…
This is not an exploitable security issue, or even not related to security at all. It cannot be used by a remote attacker in order to abuse Opera users.
Unfortunately, you have reported this problem to the wrong company. We do not own the websites that you visit (except opera.com) and we cannot control your accounts on those websites. If you are having problems with your account on a website, please contact the owners of that website.
Please report the problem to the website owner. We cannot control other websites, and their ways to block access.
Unfortunately, you have reported this problem to the wrong company. We cannot control your Facebook account nor the problems that occur on Facebook. If you are having problems with your Facebook account, please contact Facebook.
Note that some websites may display fake virus warnings, hoping to convince you to download and install malware disguised as an anti–virus product, or hoping you will contact them and follow malicious instructions. If a website tells you that you have a virus, the warning is usually fake. If you think that your phone has…